LOCAL ANESTHETIC SPREAD TO THE CONTRALATERAL TRIGEMINAL GANGLION

Abstract

Chronic neuropathic pain syndromes can severely affect a person’s quality of life. Trigeminal neuralgia is among these syndromes and involves the mandibular branch of the fifth cranial trigeminal nerve. Patients typically present with facial pain described as electrical and shock-like in nature, exacerbated by movements of the jaw such as talking and chewing. Many patients are unable to achieve adequate relief with medical management and therefore require interventions such as injections of local anesthetics, steroids, or glycerol. One method of injection uses ultrasound guidance for local anesthetic injection in the pterygopalatine fossa affecting the trigeminal ganglion. A 64-year-old woman with a history of trigeminal neuralgia presented for a trigeminal nerve block on her right side via ultrasound guidance. Following the injection, she experienced the desired effect of numbness on her right side in the distribution of the trigeminal nerve. In addition, the patient reported feeling the same effects on her left side despite no injection being done on that side. We describe a unique case in which local anesthetics spread through the pterygopalatine fossa and across the midline, affecting the contralateral trigeminal ganglion. Patients should be monitored for hemodynamic changes following this injection. Key words: Trigeminal neuralgia, trigeminal nerve block, pterygopalatine fossa, regional block, trigeminal ganglion